In a storage system, a controller module (hereinafter, referred to as a CM) performs data control for a plurality of disk devices. For example, the CM receives an input/output (I/O) command to a disk device from a host computer via a channel adapter (hereinafter, referred to as a CA), which is an interface to the host computer. Then, the CM controls output and input of data to and from the disk device on the basis of the received I/O command.
Some CAs have a dump function of recording an internal file and the memory contents as dump data (fault information). When an error occurs in a CA having a dump function, a central processing unit (CPU) in a CM collects dump data from the CA in which the error has occurred and saves the collected dump data into a storage device called a bootup and utility device (BUD) in a system. The time from collection of dump data from the CA to completion of saving of the dump data into the BUD by the CPU is referred to as a “siphoning execution time”. The processing for collecting dump data from the CA and then saving the collected dump data into the BUD is referred to as “siphoning processing”.
For siphoning processing, a specified time is set. Accordingly, a storage system may estimate the “siphoning execution time” before siphoning processing starts and may determine whether or not the processing is terminated within the specified time. Here, in the case where the estimated “siphoning execution time” is within the specified time, the storage system determines that dump data collected from the CA may be recorded into the BUD with certainty.
After the dump data is collected and saved as described above, the CA in which the error has occurred is isolated from the CM. The dump data saved in the BUD includes fault information and is used for analysis of the error in the CA and recovery from the error.
Japanese Laid-open Patent Publication No. 2007-334668, Japanese Laid-open Patent Publication No. 2000-148544, and Japanese Laid-open Patent Publication No. 11-119919 disclose related techniques.
However, in the related arts described above, recording of dump data may not be ensured. For example, since the “siphoning execution time” changes in accordance with the usage rate of the CPU, the “siphoning execution time” increases as the usage rate of the CPU increases.
Thus, even in the case where the “siphoning execution time” estimated before siphoning processing is started is within the specified time, when the usage rate of a CPU increases while the CPU is performing the siphoning processing, the actual “siphoning execution time” may exceed the specified time. In this case, the CPU does not complete the processing for saving dump data collected from the CA into the BUD within the specified time. As a result, the storage system does not save part of the dump data collected from the CA into the BUD.